1. Field of the Invention
The present invention relates to continuous batch washers or tunnel washers. More particularly, the present invention relates to an improved method of washing textiles or fabric articles (e.g. clothing, linen, etc.) in a continuous batch tunnel washer wherein the textiles are moved sequentially from one module or zone to the next module or zone including initial pre-wash zones, a plurality of main wash and pre-rinse zones, and then transferred to an extractor that removes water. More particularly, the present invention relates to an improved method of washing textiles in a continuous batch tunnel washer wherein a counter flow of wash liquor from one module or zone to the next module or zone is stopped, allowing for a standing bath. Chemicals are then added to separate soil from the goods and suspend the soil in the wash liquor. After a period of time, counter flow is commenced again to remove the suspended soil. The pre-rinsed goods are spray rinsed during extraction of excess water so that soil is not redeposited eliminated graying of the goods.
2. General Background of the Invention
Currently, washing in a commercial environment is conducted with a continuous batch tunnel washer. Such continuous batch tunnel washers are known (e.g. U.S. Pat. No. 5,454,237) and are commercially available (www.milnor.com). Continuous batch washers have multiple sectors, zones, stages, or modules including pre-wash, wash, rinse and finishing zone. Commercial continuous batch washing machines utilize a constant counter flow of liquor and a centrifugal extractor or mechanical press for removing most of the liquor from the goods before the goods are dried. Some machines carry the liquid with the goods throughout the particular zone or zones.
Currently, a counter flow is used during the entire time that the fabric articles or textiles are in the main wash module zone. This practice dilutes the washing chemical and reduces its effectiveness. Additionally, while the bath liquor is being heated, this thermal energy is partially carried away by the counter flow thus wasting energy while a desired temperature value is achieved.
A final rinse with a continuous batch washer has been performed using a centrifugal extractor or mechanical press. In prior art systems, if a centrifugal extractor is used, it is typically necessary to rotate the extractor at a first low speed that is designed to remove soil laden water before a final extract.
Patents have issued that are directed to batch washers or tunnel washers. The following table provides examples.
TABLEPAT. NO.TITLEISSUE DATE4,236,393Continuous tunnel batch washerDec. 02, 19804,485,509Continuous batch type washingDec. 04, 1984machine and method for operatingsame4,522,046Continuous batch laundry systemJun. 11, 19855,211,039Continuous batch type washingMay 18, 1993machine5,454,237Continuous batch type washingOct. 03,1995machine